C#自动生成编号

 1 public class RandomNumber
 2     {
 3         public static object _lock = new object();
 4         public static int count = 1;
 5 
 6         public string GetRandom1()
 7         {
 8             lock(_lock)
 9             {
10                 if(count >= 10000)
11                 {
12                     count = 1;
13                 }
14                 var number = "P" + DateTime.Now.ToString("yyMMddHHmmss") + count.ToString("0000");
15                 count++;
16                 return number;
17             }
18         }
19 
20 
21         public string GetRandom2()
22         {
23             lock(_lock)
24             {
25                 return "T" + DateTime.Now.Ticks;
26 
27             }
28         }
29 
30         public string GetRandom3()
31         {
32             lock(_lock)
33             {
34                 Random ran = new Random();
35                 return "U" + DateTime.Now.ToString("yyyyMMddHHmmssfff") + ran.Next(1000, 9999).ToString();
36             }
37         }
38     }